Use your smart phone efficiently, avoid mobile phone “bill shock”. Introduction of smartphone world, VoIP has progressed a lot and the smartphone users now have many ways to make free calls. Many people don’t know how to utilize this feature in their smart phones. iPhone has a lot of VoIP apps available in the iTunes app store but unfortunately they are not all very useful.

Here, we have hand picked 5 iPhone apps tested all those and using for a while and sharing here to make your life easy. None of them eating your minutes or your monthly limit. Most of these are independent applications using your WiFi / 3G / 4G network to make calls.

FaceTime: FaceTime for iPod/iPhone/iPad/MAC makes it possible to talk, smile, and laugh with anyone on an iPad 2, iPhone 4, iPod touch, or Mac. So you can catch up, hang out, joke around, and stay in touch with just a click. Sure, it’s great to hear a voice. But it’s even better to see the face that goes with it.

FaceTime is easy to set up. FaceTime works perfectly with Address Book so you don’t have to enter your contacts from scratch. Click her phone number if you want to call her iPhone 4.

To call her iPad, iPod touch, or Mac, use her email address. An invitation pops up on her screen. When she accepts, the video call begins. And there you are, face to face. Mac to iPad, iPhone, iPod touch, or Mac.

You can talk to any of your Facebook friends and make free calls to any phone in US, Canada, and Puerto Rico

With a universal way to communicate, Bobsled users can easily message or call for free across devices, countries, social networks, operating system – and all mobile carriers.

Bobsled will find your friends on Facebook or their iPhone/iPad/iPod Touch, and connect the call. If they are not there, send chat messages right from the app. Always stay connected with your friends.

You have to login with either email or Facebook to make free calls. It can use to receive calls from your Facebook friends, Chat with your Facebook friends and you can leave Voice Messages

Talkatone: Free Google Voice, GTalk and Facebook VoIP phone calls and text. The only app that lets you call and text any phone number in US and Canada without requiring them to install Talkatone.

You can make Call and text your Facebook and Google friends for free, anywhere over WiFi or 3G/4G.

Talkatone doesn’t use cell minutes and there are no SMS fees. You need a free google voice account to connect with Talkatone.

Tango Video Calls: Tango is the only app that lets you make free video calls, phone calls, and send free video messages to a tango member. It is allowing the great feature of free Group Video Messaging. You can now record and share personal videos with anyone in your contacts list.

You can send and receive free video messages, Group video messaging and share with multiple people at once. You can send video messages to friends who don’t have Tango and you can view your sent messages & forward to others.

Viber: Free Phone Calls & Text: Viber lets everyone in the world connect freely. More than 40 million Viber users call, text, send photos and locations with each other worldwide for free with no subscriptions or purchases.

You can call and text other users, on any network, as much as you want. All you need is a 3G or Wi-Fi Internet connection, and friends who get Viber too. Viber just works, and lets you connect with your friends whose numbers you already have.

It syncs with your mobile phone number and contact list to instantly show who already has Viber. Never again must you seek out your own contacts, create new user names, or build new lists.

Viber runs in the background without draining your battery, so you always receive incoming calls and message notification.